This invention pertains to electronic switches and, more particularly, to a Gallium Arsenide field effect transistor switch in which the bias voltage necessary to operate the GaAs transistors is produced from a voltage multiplier-rectifier-filter circuit which is powered from an input signal to the switch.
GaAs transistors have been used in electronic switches and are sometimes preferred over PIN diodes because these transistors can be integrated on a monolithic integrated circuit chip and because they dissipate negligible power in the ON state. GaAs transistors are usually preferred over other field effect transistors because of their high frequency operating characteristics. GaAs transistors, however, are depletion mode devices which require a negative bias voltage (for an N-channel device) between the gate and source terminals to switch the transistor to the OFF state. This usually requires an additional power supply to operate the switch.
The GaAs switch described below, however, eliminates the need for an addtional bias voltage supply. This invention uses a voltage multiplier, rectifier and filter circuits to derive the necessary bias voltage directly from an input signal to the switch.